def build_rule(l, r, cons=None):
lpat = []
rpat = []
sym = set()
cons = cons or {}
for pat, bind, ty in free(l):
if bind in sym:
# TODO unify ty
lpat.append(bind)
else:
lpat.append(bind)
sym.add(bind)
for pat, bind, ty in free(r):
if bind in sym:
rpat.append(bind)
else:
raise Exception('Unbound variable: %s' % pat)
left = freev(l)
right = freev(r)
ana = partial(unfold, lpat, left)
cata = partial(fold, rpat, right)
rr = partial(hylo, ana, cata)
return Rule(lpat, rpat, left, right, rr)
def test_aspattern3():
a0 = dslparse('b: a@f(x,y) -> a')
v = free(a0[0].lhs)
f = aparse('f(x,y)')
assert list(v) == [
(f, 'a', ast.aappl)
]
def test_aspattern1():
x = aparse('x')
a0 = dslparse('b: f(a@x) -> a')
v = free(a0[0].lhs)
assert list(v) == [
(x, 'a', ast.aterm)
]
def test_linear():
x = aparse('x')
y = aparse('y')
a0 = aparse('f(x,y)')
v = free(a0)
assert list(v) == [
(x, 'x', ast.aterm),
(y, 'y', ast.aterm)
]
def test_aspattern2():
a0 = dslparse('b: @f(x,y) -> a')
v = free(a0[0].lhs)
f = aparse('f')
x = aparse('x')
y = aparse('y')
assert list(v) == [
(f, 'f', ast.aterm),
(x, 'x', ast.aterm),
(y, 'y', ast.aterm)
]